1. Field of the Invention
The present invention relates to an aircraft passenger seat, particularly but not exclusively to an aircraft sleeper seat convertible into a substantially flat bed.
2. Background Art
Examples of prior art aircraft sleeper seats are disclosed in the applicant's patent publications WO 96/18537 and WO00/21831, embodiments of which include the current British Airways First and Club World seats respectively. Both of these seats can be converted into a flat, horizontal bed, and have enjoyed great commercial success. However, there is intense competition to provide ever-greater comfort and space for aircraft passengers.
Passenger seats for aircraft are subject to stringent design constraints, many of which are not applicable to seats for other vehicle types. One problem is the need to meet the relevant safety standards for aircraft passenger seats, such as the 16 g test that requires seats to survive deceleration of 16 g in a takeoff/landing position. Another problem is the need to minimize the weight of the seat, since carrying extra weight on an aircraft increases fuel consumption and therefore monetary and environmental cost. Hence, the seat must be both strong and light.
Another problem relates to the use of space. Any given aircraft has a maximum area for passenger seating, which must be used in the most space-efficient manner possible so as to maximize the seating area and legroom available to each passenger, while allowing unimpeded exit from the seat. It is also important for cost reasons to fit as many passenger seats as possible in the available area.
Another problem relates to the level of comfort of the seat. Aircraft passenger seats may be used for day flights, in which the passenger will want to work, eat and/or relax, and night flights during which the passenger will want to sleep. Preferably, an aircraft passenger seat should be able to adopt comfortable positions for all of these activities, yet also be able to meet the relevant safety standards in a takeoff/landing position.
Another problem relates to the psychological and/or social needs of aircraft passengers, who may desire privacy while working, eating or sleeping, or may wish to interact with a travelling companion. There are also some arrangements that are undesirable for aesthetic and/or psychological reasons; for example, it is preferred that parts of the seat mechanism are not visible to the passenger.
Patent publication EP-A-1 116 654 (BE Aerospace) discloses an aircraft passenger sleeper seat that can adopt fully upright, semi-reclined or lounge and fully reclined or sleep positions. The seat includes an ottoman that functions as a foot or leg support, and has a top cushion and a pivoting legrest cushion.
U.S. Pat. No. 2,583,223 (Mayer) discloses a foot and leg rest for passenger vehicles, having a rearwardly inclined foot rest position and an elevated, forwardly inclined leg rest position.
Patent publication WO 98/36967 (Singapore Airlines) discloses an aircraft passenger seat with armrests that are lowered as the seat reclines, so as to lie flush with a seat portion in a fully reclined position and thereby improve the width available to the passenger.
U.S. Pat. No. 6,692,069 (Beroth et. al.) discloses an aircraft passenger sleeper seat in which an armrest pivots forwards as the seat reclines, so as to be aligned with a seat bottom in a fully reclined position and thereby improve the width available to the passenger. However, this arrangement does not allow the sleeping surface to be horizontal.